Arrangement of electrodes for the electrolytic refining of metals.



' F. M. K'OHLER. ARRANGEMENT 0F ELECTRODES FOR THE ELECTROLYTIC BEFINING0F METALS. APPLIOATION FILED DEC. 28, 1909.

1 ,005 ,7 1 8. Patented Oct. 10, 1911.

2 SHEETS-SHEET 1' FIE-4- 7 F :I m A mmesses p L Inventor COLUMBIAPLANOGRAPH CO.,WAS"INGTDN D c I. M. K'OHLER.

ARRANGEMENT 01 ELECTRODES FOR THE ELECTROLYTIC REFINING OI METALS.

APPLICATION FILED DEC. 28, 1909.

1,005,? 1 8. Patented 001. 10, 1911.

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WM MAZM l'vornqys LOLUMHIA PLANOGRM'H C0.,WASIIINGTON, 1). c4

FRIEDRICH MAX KfiHIaER, OF ST. PETERSBURG, RUSSIA.

ARRANGEMENT 0F ELECTRODES FOR THE ELECTROLYTIC REFININGOF METALS.

Specification of Letters Patent.

Patented Oct. 10, 1911.

Application filed December 28, 1909. Serial No. 535,327.

To all whom it may concern:

Be it known that I, FRIEDRICH MAX Kort- LER, a subject of the Emperor ofGermany, residing at St. Petersburg, in the Empire of Russia, haveinvented certain new and use ful Improvements in the Arrangement ofElectrodes for the Electrolytic Refining of Metals; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention consists in an arrangement and apparatus for theelectrolytic refining of metals which derives its material technicaladvantages from the fact that an electrolytic cell is formed of twooppositely arranged plates, consisting of the metal to be refined, sothat the containers, tanks or the like now required can be dispensedwith. The electrolytic process is utilized free from any secondarychemical reactions or influences occasioned by secondary lateralelectric currents or short circuits during the passage of theelectrolyte through the cell and to and from the auxiliary containers,the process acting thereby on each pair of electrodes independently ofthe others. Further, the electrolyte being in this arrangement excludedfrom contact with the air, it is rendered practically possible to employelectrolytic solutions which give twice the quantity of metal depositowing to the fact that the salts of oxids of a lower stage are dissolvedin such electrolytes and kept in solution during the whole process. Aparticular advantage of the invention consists further in making visiblethe field of work of the cell, since this arrangement facilitates thecontrolling of the process, the formation of the degrees of oxidationbeing discernible by the alteration of the color of the electrolyte. Inall processes which have hitherto been employed for such electrolyticrefining, separation or plating the electrolyzing operations are carriedout in open vessels, baths or the like filled with the electrolyticsolutions; and current conducting bars are usually arranged above thevessels and 011 them are hung the several electrode plates, anodes andcathodes, immersed in the electrolyte solution. It has been found thatthis method of arranging the electrodes can only be employed with thoseelectrolytes with which access of the air and the possibility ofoxidation are allowable without of the fittings above the baths producescurrent deviations and short-circuits, which limit the quantity of metaldeposit. The means hitherto proposed for keeping the electrolytesolution in circulation do not preclude the defects above mentioned,because these means do not remove the deposits or sludge from the fieldof work of the electrolytic process. Furthermore, there has hitherto notbeen found a practical method for excluding the air from contact withthe electrolyte by means such as n1echanical closure and other devicesarranged on the vessels or by the employment of an air excludingsubstance, such as oil or grease. Likewise all attempts to make theprocess visible in order that it may be controllable have hitherto notgiven results fit for use in practical working for baths of largersizes. On the other hand practical chemists have for a long timerecommended electrolytic processes which are in many respects superiorto the methods followed hitherto, provided that the electrolyte,remaining insulated from contact with the air, is kept in active motionand works in an always clear field exempted from the influence ofsecondary processes.

According to the present invention an entirely new arrangement ofelectrodes is employed composed substantially of the electrolytic cell,the electrolyte containers and the current conductors.

In the accompanying drawings Figure 1 shows front and side views of oneanode plate A and Fig. 2 similar views of the other anode plate A bothof said plates constituting the metal itself, which is to be refined.Fig. 3 shows front and side views of the cathode plate K. Fig. 4 showsone of the two intermediary frames R and Fig. 5 the second intermediaryframe R F i 6 shows a part of the assembled cell with the front half ofsame taken off, thus displaying the cathode K and the frame R Fig. 7 isa cross section and Fig. 8 an external general view of the assembledcell respectively. Figs. 9, 10 and 11 show a modification in theconstruction of the cell.

; valve 1".

In this modification Fig. 9 shows the frame It. Fig. 10 a part of thecell corresponding to Fig. 6; and Fig. 11 shows a cross section of thecell corresponding to Fig. 7

Lastly, Fig. 12 is aview of the general disposition of the cells and ofthe means for connecting same with the electrical circuit. In thisfigure cells I and II are constructed according to Figs. 6 and 7 andcells III and IV, according to Figs. 10 and 11.

The electrolytic cell is composed, as will be seen on reference to theaccompanying drawings, of the two anode plates A and A (Figs. 1 and 2),the cathode plate K (Fig. 3) and the intermediary frames R and R (Figs.4.: and 5). These frames are made of a material which resists thechemical action of the electrolyte and is nonconducting electrically.

The sides of the frames may be wholly or partly of transparent material,for in stance, glass. Into the sides of the frames which adjoin themetal anode plates is inserted an elastic collar of rubber to make atight closure. Through the top side of the frame B (Fig. i) passes theconnecting tube r provided with the air exhausting There is also letinto the side of the bottom of the frame a metal block m which, with thecorresponding metal block of in the frame R forms the clamping contactfor the cathode plate K (Fig. 7) and supplies it with current from themain bar.

Through the bottom of the frame 1 (Fig. 5) passes the connecting tube 1and it is into this side of the frame that the metal block m is let. Byusing two cathodes, however, and one anode plate, or by combiningseveral cells in one it is possible to alter the form of the cell.Similarly the contact blocks m and m can be let into the top sides ofthe frames R and R so that one pole joins the contact below in the celland the other above. (Figs. 9, 10 and 11; also III and IV on Fig. 12).The tubes r and rare provided with valves h and 77/2 respectively.

In mounting the cell according to Figs. 6, 7, 8, or I and II in Fig. 12the parts are put together in the following order: A B K, B A and theyare then all clamped together by the clamping device M (Fig. 8).

The means for taking in the electrolyte solution consists of thecontainer with connecting pipes, taps and a coil shaped heater Z. Thiscontainer serves to hold the freshly prepared, or renovated electrolyte,or the solution coming from the container which is likewise furnishedwith connecting. pipes and taps, and also with sludge collector H andfiltering chamber F, and finally with pumps P and P and the necessaryconnection pipes.

The means for furnishing the current consist of a stable rigid platformin which channels are recessed to take metal bars; these are notconnected with the platform or with the earth, but are insulated onglass supports.

The apparatus operates as follows :-The electrolyte solution is admittedfrom collecting reservoirs to the container and ifnecessary heated. Thevalve k above the frame is then opened and the valve 7L2 below the frameclosed. The electrolyte is thus admitted into the cell forcing the aircontained therein through the valve 7 and the latter is closed as soonas the cell is full. The valve 72, below the frame is then opened againand the electrolyte flows into the container 7 It is drawn off by thebump P and led back tothe container W after first passing through thesludge collector and filtering chamber formed in divisions of thecontainer II, and collecting in sufficient quantities in the filteringchamber of the container In this manner a continuous circulation of theelectrolyte is effected and the latter is set in motion so that thedissociation of the anode ions is assisted. As the sludge or depositwhich is separated out from the anodes, is carried away with thesolution, the anodes are kept clean and the formation of sediments,which so injuriously affect electric current with a large working field,is prevented. As at the same time oxidation of the electrolyte by theair is prevented, salt-s of oXids of the electrolyte of a lower stageare formed at corresponding current densities and compounds are producedby which quantitatively larger amounts of metal particles are freed fromthe anodes than it would be at the same expenditure of current with anelectrolyte from which air is not excluded and which is not circulatedin the manner described.

With this system it is actually rendered practically possible to employoxids of proto salts, these proto salts, that are themselves insoluble,forming chemical compounds by means of which, owing to the prevention ofoxidation by admission of air, they are kept in solution. Such protosalts are known to give twice the quantity of metal deposit, given bythe compounds in per salt solutions for the same consumption of current.This arrangement also offers advantages in connection with the erectionof metal refining plants in which neutral or alkali electrolytes areemployed, capable only of dissociating a particular metal. Foreignbodies and other metals which may be contained in the anode plates, arenot dissolved in a solution having such limited properties, nor are theytransferred to the cathode, but are deposited as sludge. As it isrendered impossible that gathering of such sludge should take place atthe bottom of the cells, the field of work of the electrolytic processitself remains always clean and the electrolyte is not affected by anysecondary influences; also deviations and short-circuits occasioned bythe contamination of the fittings are prevented, as these fittings aredisposed outside the field of work. According to the present inventionthe entire removal of the sludge from the field of work is an extremelysimple matter and can be effected at any time without interrupting theworking of the plant. The sludge collecter H in the container W can bequickly removed and the filter when choked can as quickly be replacedwith new ones. Moreover, testings of the electrolyte can be taken at anytime for the purpose of analysis from various points of the field ofwork, and fresh or renovated solution may be added during the working ofthe plant.

The arrangement for carrying the circuit conductors is extremely simplein construction, and all kinds of connection contacts are avoided. Thethick anode plates rest with the whole of their lower surfaces upon theconducting bars m as also do the cathode plates K by means of theclamping blocks m and m when these are arranged at the bottom of theframes. For refining very impure metals the cathode contacts should beattached to the upper sides of the frames (Figs. 10 and ll-III and IV inFig. 12). This obviates any possibility of short-circuits being formedat the bottom of the cell even with deposits from the anode very rich inmetal, for with this new arrangement the cathode hangs free in the celland the poles, where the current enters and leaves are separated fromone another. In any case a good contact is insured here for transmittingthe current, as the current lies beyond the reach of the oxidizingelectrolyte solution, which cannot be done with open tanks, that beingone great objection to the latter type of apparatus.

Each cell is a unit complete in itself, and works independently of everyother cell; it can be removed from the line of cells at any time in afew minutes; the cells are moreover coupled up in series one behind theother, whereby the utmost use is made of the current.

I claim 1. An electrolytic cell for refining metal comprising anodesconsisting of the metal to be refined and separated by a frame, theanodes and frame forming a container for an electrolyte, and a cathodearranged in the container, substantially as described.

2. An electrolytic cell for refining metal comprising anode platesconsisting of the metal to be refined, a frame arranged between theanode plates forming with the anodes a container for an electrolyte, theframe having a transparent side, acathode arranged in the container, andmeans for supplying the electrolyte to the container, substantially asdescribed.

3. An electrolytic cell for refining metal comprising anode platesconsisting of the metal to be refined, a frame arranged between theanode plates forming with the anodes a container for an electrolyte,means for binding the anode plates to the frame, a cathode arranged inthe container, and

'said container provided with pipes for the supply and discharge of theelectrolyte, substantially as described.

4. The combination of a number of electrolytic cells arranged in seriesfor refining metal, each cell comprising anode plates consisting of themetal to be refined and separated by a frame forming with the anodes acontainer for an electrolyte, the frame having a transparent side, meansfor binding the anode plates to the frame, a cathode arranged in eachcontainer, each container provided with pipes for the supply anddischarge of the electrolyte, the pipes being provided with means forexcluding air from said container, and means for connecting the anodeplates of one container to the cathode plates of the adjacent container,substantially as described.

In testimony whereof, I aflix my signature, in presence of twowitnesses.

FRIEDRICH MAX KoHLEn.

Witnesses H. A. LOVIAGEIW, A. MIGHIS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

